Study On Preparation And Properties Of Fe65 Powder Plasma Cladding Layer Modified By Multicomponent Alloy

In the modern automobile manufacturing,machinery,power and engineering equipment manufacturing and other fields,hot work die work in high temperature environment for a long-term time,and bear the role of a large variable load.If the mechanical properties of the forging die material is poor,the service life of the hot forging die will be greatly affected,thus affecting the quality of forgings,and increasing the cost of production,so the choice of forging material becomes more important.In this paper,a multi-alloy reinforced ortho-experimental cladding layer with self-fluxing Fe65 as the base component was prepared on the H13 steel substrate by micro-beam plasma cladding.The microstructure,element distribution and phase composition of the coatings were studied by using EPMA,XRD,OM and other microscopic observation and testing equipment.The performance of the coating was characterized by hardness tester,ball disc wear tester,gleeble simulation machine and resistance furnace.Al,W,V elements are used as the influencing factors,and every element select three content values as a horizontal parameter.The coating samples were mainly analyzed by microstructure and tempering hardness,therefore finding the best recipe group.The results show in the microstructure of the orthogonal experimental group of cladding layer the matrix phase is fine austenite containing Al,Cr,W and other elements,the grain boundary is distributed with short needle FeAl and Fe₃Al intermetallic compounds,Cr₇C₃,WC,VC and carbide dendrites.Compared with the air cooling,the hardness of the orthogonal group cladding layer is significantly improved after 700 degrees high temperature tempering,and the hardness of the orthogonal group 8H cladding layer(566HV_0.1)increases the most,therefore selected as the best ingredient formula coating.After high temperature tempering,the hardness of the reference group 10J cladding layer(379HV_0.1)decreased significantly,and the hardness of H13 steel was smaller.On the basis of orthogonal coating research,8H coating's performance would be compared with the Fe65 coating,H13 steel by Gleeble thermal simulation.The results show that the samples have different degrees of hardening in the first four compression cycles,and the performance of each sample in the fourth compression cycle is selected as the effective data before the failure of the sample material.Comparing and calculating elastic modulus of 8H,Fe65,H13 samples found that elastic modulus of the 8H coating is 85.9GPa,respectively equivalent to 111.7%,135.7%of Fe65 coating,H13 steel.Indicating that the thermal strength of the 8H coating is better,which is beneficial to reduce the plastic deformation of the membrane surface.Friction and wear experiments found that friction coefficient of8H coating is smallest,wear is least,so anti-friction and wear performance is better than that of Fe65 coating and H13 steel.This is due to the addition of Al,W,V and other elements in 8H cladding,playing a grain refinement and improving the heat intensity.In the high temperature oxidation experiment,8H coating showed better resistance to high temperature oxidation.Most of of the coating surface field present metallic luster,and oxidation is mainly present in the microdomain of dotted particles.This is related to the coexistence of Cr₂O₃ thin films and Al₂O₃ films in the coating.In summary,the comprehensive performance of 8H coating is significantly better than Fe65 base cladding material and H13 steel,which have an important reference value for hot forging die surface modification studies.